Pheidole obtusospinosa Pergande

Wilson, E. O., 2003, Pheidole in the New World. A dominant, hyperdiverse ant genus., Cambridge, MA: Harvard University Press, pp. -1--1: 587

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Pheidole obtusospinosa Pergande


Pheidole obtusospinosa Pergande  HNS 

Pheidole obtusospinosa Pergande  HNS  1896: 889. Junior synonym of Pheidole subdentata Pergande  HNS  1896: 888, synonymy by Wheeler, 1914c: 50; subdentata Pergande  HNS  is ajunior secondary homonym of Oecophthora subdentata Mayr  HNS  1853b: 145, later transferred to Pheidole  HNS  and a synonym of P. pallidula (Nylander)  HNS  of Eurasia; hence obtusopilosa  HNS  is first available name. Syn.: Pheidole arizonica Santschi  HNS  191 ld: 3, synonymy by Creighton 1958: 211.

Types Nat. Mus. Nat. Hist. U. S.

Etymology L obtusospinosa  HNS  , with blunt thorns, referring to the propodeal spines.

Diagnosis A large trimorphic species placed in the pilifera  HNS  group because of the 2-toothed hypostoma of the major but with other traits conforming to the fallax  HNS  group. Very close to hirtula  HNS  , distinguished most readily in the supermajor, as illustrated, by the elongate foveae of the rear half of the dorsum of the head, with the interspaces densely foveolate and opaque. The tangled taxonomic history of this species and the true status of vaslitii  HNS  , previously associated with it but now revealed as a junior synonym or sibling species ofhyatti (q.v.), have been presented by Ward (2000).

Measurements (mm) Supermajor: HW 2.50, HL 2.36, SL 1.12, EL 0.26, PW 1.06.

Major: HW 1.44, HL 1.46, SL 1.12, EL 0.24, PW 0.72.

Minor: HW 0.62, HL 0.80, SL 0.98, EL 0.16, PW 0.44.

Color All castes: yellowish to reddish brown.

Range Known from the mountains of southern Arizona at 300-1900 m, and from Nayarit to Nuevo Leon in Mexico.

biology Stefan Cover (unpublished field notes), who has collected obtusospinosa  HNS  many times in southern Arizona, has found it consistently in woodland, variously composed of different combinations of pine, oak, and juniper. It typically nests under rocks, although Cover found one colony beneath a cow pat and another 2.5 m from the ground in the dead branch of a standing oak tree ( Quercus arizonica  HNS  ). Creighton (1958) reports that colonies are much smaller than those of the closely related hirtula  HNS  , and that in southern Arizona nuptial flights occur in early July.

Figure Upper: major, with heads of major (left) and supermajor (right). Lower: minor. ARIZONA: Sunnyside Canyon, Huachuca Mts., Cochise Co. (Stefan Cover). (Type locality: Tepic, Nayarit, collected by Eisen and Vaslit.) Scale bars = 1 mm.